View Full Version : Fmu

03-06-2008, 08:42 PM
Yeah yeah yeah.... i know. They suck.


Does anyone on here have experience with them on Toyota engines?

If i had something to retard the timing for safety, what else would i really need in terms of management to boost a car on the cheap?


And pretty much done.

Has anyone used an FMU on a 5sfe/4afe/4age/3sge/3sfe/7afe?

03-06-2008, 09:27 PM
I haven't ventured into the turbo realm.

Not for a while anyway.

03-06-2008, 09:49 PM
You would need to use the MSD BTM in conjuntion with the FMU. Ditch the SAFC and add a 2 bar map sensor and use the 88-89 RX7 N/A 450cc injectors.

03-06-2008, 09:54 PM
^Even better.

Have you personally used FMU on any of these engines? Consider it a viable cheap alternative while still retaining some measure of safety?

I know honda guys use it to great success, and i've seen and driven the results first hand and i've been pretty impressed for something as simple as it is.

03-06-2008, 09:59 PM
I never got the chance to run a fte setup. There was a guy from the old cnet days Todd that did his 5s auto with a FMU. It worked well for him. The 2 bar map will cut the injector duty in half allowing for near stock flow until boost hits. Much better than a SAFC I've actually got a set of the RX7 injectors that I never used.

03-06-2008, 10:12 PM
Man, you gotta pay to play with that MSD BTM, don't you....

I guess it's still a good deal overall, but i wasn't expecting to be quite that much. :P

Thanks for the info, i'll do some more digging and see what i can find.

Actually, durrrr....

It's not that bad, didn't realize that the part number 6462 replaces the ignition, too. :)

03-07-2008, 04:30 PM
FMU: Check. ($40 woot woot)
Turbo: Check.

03-07-2008, 09:18 PM
Can someone explain to a nub what a "FMU" is?

03-07-2008, 09:53 PM
^Fuel Management Unit.


03-10-2008, 03:16 PM

So basically, the BTM will take care of retarding the timing to prevent detonation, and the 2bar Map sensor would correct for the 450s?

Or am i missing something? On every boosted honda i've done, we've always had to at least have an SAFC if we're going to be running bigger injectors, just to prevent it from running so rich it bogs.

Or we just run stupid amounts of psi through the stock injectors on the FMU as a band-aid fix.

What happens with our cars? I still don't need anything to control fuel beyond map sensor, injectors, and fmu, right?

03-10-2008, 10:44 PM
A fmu is the cheap way, the better way would be an AFPR. The 2bar will read half as much as the stock 1bar knocking the injectors to 225s stock is something like 212-215. Once the map reads positive pressure it will add the right amount of fuel. The BTM can be set to retard X amount of timing for X amount of boost.

I cant tell you what the base pressure for the 450s are, ours is something in the 40s. Your best bet would be to get a wideband and watch what afrs your running while boosting. If correction is needed get the SAFC. Your more than likely going to be running rich so lean it out with the SAFC. The FMU will add to the fuel pressure but that might not be needed. The old Burien kit didn't use a fmu just 360 Supra injectors and a 2bar.

03-11-2008, 02:25 PM
Hrmmm..... even better...

So i should just start with 2bar, and injectors, and see if it runs like ass. :P

Not that i'm complaining, i know you gotta pay to play, i was just thinking that there was possibly a relatively cheap way to do this without running huge risk of blowing the engine.

Looks like we're more of a pain in the ass than Hondas.

I'll probably post back tomorrow with more questions, i have to do some more research. :)

Thanks for all your help so far